Joining a list of python objects with __str__ method

Question

I\'ve already looked at this question on representing strings in Python but my question is slightly different.

Here\'s the code:

>>> class W         


        

Answer 1

There are probably no amazing way.

def strjoin(glue, iterable):
    return glue.join(str(s) for s in iterable)

Answer 2

"...it would be nice to avoid doing that every time..."

You want to avoid repeating that same code multiple times? Then use a function;:

def join_as_str(alist):
    return "\n".join(str(item) for item in alist)

Answer 3

You technically aren't joining the list of python objects, just their string representation.

>>> reduce(lambda x,y: "%s\n%s" % (x,y), weird_list)
'1302226564.83\n1302226564.83\n1302226564.83'
>>> 

This works as well but doesn't look any nicer:

>>> a = ""
>>> for x in weird_list:
...     a+="%s\n" % x
... 
>>> print a
1302226564.83
1302226564.83
1302226564.83

>>>

Answer 4

Would it work for you if you added an __add__ method? E.g.,

from operator import add
from random import randint

class WeirdThing(object):
    def __init__(self,me=None):
        self.me = me if me else chr(randint(97,122))
    def __str__(self):
        return "%s" % self.me
    def __repr__(self):
        return ";%s;" % self.me
    def __add__(self,other):
        new_me = add(str(self.me),str(other.me))
        return WeirdThing(new_me)

weird_list = [WeirdThing(), WeirdThing(), WeirdThing()]
print weird_list

gives,

[;y;, ;v;, ;u;]

and this,

strange_thing = reduce(add,weird_list)
print strange_thing

gives,

yvu

Answer 5

You have to stringify your objects before you can join them. This is because str.join expects a series of strings, and you must give it a series of strings.

For the sake of less typing at the cost of readability, you can do "\n".join(map(str, list_of_things).